<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="../css/reset.css">
    <style>
        .phone {
            width: 300px;
            height: 500px;
            border: 1px solid #333;
            margin: 100px auto;
            position: relative;
        }

        .slideBar {
            width: 100%;
            height: 50px;
            background-color: darksalmon;
            position: absolute;
            top: 60%;
            left: 0;
        }

        .ball {
            width: 50px;
            height: 50px;
            background-color: green;
            position: absolute;
            left: 0px;
            top: 0;
            border-radius: 50%;
        }
    </style>
</head>

<body>
    <div class="phone">
        <div class="slideBar">
            <div class="ball"></div>
        </div>
    </div>
</body>
<script>
    var phone = document.getElementsByClassName("phone")[0];
    var slideBar = document.getElementsByClassName("slideBar")[0];
    var ball = document.getElementsByClassName("ball")[0];

    var maxLeft = slideBar.clientWidth - ball.clientWidth;

    ball.onmousedown = function (e) {
        var e = e || window.event;
        // if (e.button != 0) return false;

        var posX = e.offsetX;
        // var posY = e.offsetY;

        document.onmousemove = function (e) {
            var e = e || window.event;

            var x = e.pageX - phone.offsetLeft - posX;

            if (x < 0) x = 0;
            if (x > maxLeft) x = maxLeft;

            ball.style.left = x + "px";
            if (x >= maxLeft) {
                // alert("解锁成功!");
                document.onmousemove = null;
                location.href = "https://www.jd.com";
            }

        }

        document.onmouseup = function () {
            document.onmousemove = null;

            if (ball.offsetLeft < maxLeft) {
                ball.style.left = 0 + "px";
            }

        }



    }



</script>

</html>